Hi Gustavo,

On 2025-03-28 08:33:22-0600, Gustavo A. R. Silva wrote:
> -Wflex-array-member-not-at-end was introduced in GCC-14, and we are
> getting ready to enable it, globally.
> 
> Use the `DEFINE_RAW_FLEX()` helper for an on-stack definition of
> a flexible structure where the size of the flexible-array member
> is known at compile-time, and refactor the rest of the code,
> accordingly.
> 
> So, with these changes, fix the following warning:
> 
> drivers/leds/leds-cros_ec.c:70:40: warning: structure containing a flexible 
> array member is not at the end of another structure 
> [-Wflex-array-member-not-at-end]
> 
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
> ---
>  drivers/leds/leds-cros_ec.c | 26 +++++++++++---------------
>  1 file changed, 11 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/leds/leds-cros_ec.c b/drivers/leds/leds-cros_ec.c
> index 275522b81ea5..6eab0474f52d 100644
> --- a/drivers/leds/leds-cros_ec.c
> +++ b/drivers/leds/leds-cros_ec.c
> @@ -66,24 +66,20 @@ static int cros_ec_led_send_cmd(struct cros_ec_device 
> *cros_ec,
>                               union cros_ec_led_cmd_data *arg)
>  {
>       int ret;
> -     struct {
> -             struct cros_ec_command msg;
> -             union cros_ec_led_cmd_data data;
> -     } __packed buf = {
> -             .msg = {
> -                     .version = 1,
> -                     .command = EC_CMD_LED_CONTROL,
> -                     .insize  = sizeof(arg->resp),
> -                     .outsize = sizeof(arg->req),
> -             },
> -             .data.req = arg->req
> -     };
> -
> -     ret = cros_ec_cmd_xfer_status(cros_ec, &buf.msg);
> +     DEFINE_RAW_FLEX(struct cros_ec_command, msg, data,
> +                     sizeof(union cros_ec_led_cmd_data));
> +
> +     msg->version = 1;
> +     msg->command = EC_CMD_LED_CONTROL;
> +     msg->insize  = sizeof(arg->resp);
> +     msg->outsize = sizeof(arg->req);
> +     *(struct ec_params_led_control *)msg->data = arg->req;

To be honest this looks really ugly and it's not at all obvious what is
going on. We have the utility function cros_ec_cmd() which would be the
nicer alternative. (Without having verified that it avoids the warning).
While it is slightly more expensive, I don't think it matters.
And if it does, the helper can be optimized.

(The same goes for my other cros_ec drivers)

> +
> +     ret = cros_ec_cmd_xfer_status(cros_ec, msg);
>       if (ret < 0)
>               return ret;
>  
> -     arg->resp = buf.data.resp;
> +     arg->resp = *(struct ec_response_led_control *)msg->data;
>  
>       return 0;
>  }


Thomas

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